1. Field of the Invention
This invention relates to an alternating current voltage regulator which clips an alternating current input wave form at a controlled level to produce a regulated alternating current output voltage and which automatically varies the controlled level in response to changes in load current. More particularly, the invention is concerned with a device having two electrically independent regulating sections, one for the positive portion of the alternating current cycle and the other for the negative portion of the alternating current cycle, which sections are able to independently adjust the controlled level of the regulated output voltage.
2. Description of the Prior Art
Typical alternating current voltage regulators produce a regulated alternating current output by using a direct current power source in combination with an oscillator to produce a voltage regulated, alternating current output wave form. The D.C. power source is usually contained within the regulator to receive and filter a standard alternating current input (e.g., 120 V.A.C.). This arrangement is expensive because of the numerous components involved and is inefficient from a power-consumption standpoint because of the losses incurred in amplifying an oscillator generated signal to the proper voltage level.
A second problem with known alternating current voltage regulators is that they do not automatically increase their output voltage in response to increases in load current. Transmission line losses occurring between a regulator and the load typically go up as load current goes up. Because of this, voltage actually delivered to the load may go down even though the output of the regulator remains at the proper level.
This problem is particularly acute if a transformer is part of the regulator load. As load current from the secondary of the transformer goes up, the internal "copper losses" of the transformer go up also thus causing a drop in secondary output voltage even though the regulator supplying the primary of the transformer continues to provide a constant, regulated voltage.
Because of the line-loss problem, the arrangement shown in FIG. 1 is typically used wherein each individual load is supplied by its own dedicated regulator which in turn is supplied by its secondary of the transformer. In this way, each dedicated regulator compensates for any voltage drop in the secondary of the transformer and furthermore ensures a constant output voltage delivered to each load. This arrangement while effective is expensive because it requires a dedicated regulator for each load rather than one regulator supplying the primary of the transformer.